1.2 History behind the formation of Internet
The internet is the interconnection of thousands of networks. The ARPANET began as a US Government experiment back in 1969. ARPA the Department of Defense (DoD) advanced research project agency, initially linked researchers with a remote computer centers, allowing them to share hardware and software resources such as computer disk space, databases and computers. Later, this was shortened as “Internet”.
The network operated with a technique called packet switching , in which the digital data is transmitted in small bundles called packets. These packets contain the information about the address, error control and the order in which packets are to be sent. The address information allows the packets to trace the route to their destination. The sequencing information allows the reassembling of the packets into their original order in destination. Packets from different senders were intermixed on the same line. This technique greatly reduced the costs when compared with the dedicated communication line.
The network was designed to operate without centralized control. If a portion of network failed, the remaining working portions would still route packets from senders to receivers over alternative paths.
ARPANET used the Transmission control protocol known as TCP for communication . TCP ensure that messages were properly routed from sender to receiver. More information about TCP protocols will be discussed later.
As the Internet evolved, organizations implemented World Wide Web for both intra organization (i.e.within the organization) and inter organization (i.e. between various organizations?). A challenge was raised to communicate with different networks. ARPA solved the problem by developing the Internet protocol (IP), which truly created the network of networks, the current architecture of Internet. The combination of IP and TCP is commonly referred as TCP/IP protocol.
Initially, the Internet usage was limited to universities, military organizations and research institutions. Eventually the government t decided to allow access to the Internet for commercial purpose.